This invention relates to a new and improved filling device for filling an injection syringe, the device providing a sound indicator to enable the user to accurately determine the amount of liquid medicine drawn into the syringe. The filling device of this invention is particularly suited for insulin injection by patients with impaired vision.
Various prior publications concerning these devices are to be found in U.S. Pat. Nos. 3,840,011; 3,935,883; 3,965,945; 4,018,223; 4,489,766; 4,501,306; and, 4,617,016. However, these prior art devices tend to be complicated and expensive. Moreover, many of these devices do not deal effectively with the problem of vision impaired persons who are frequently unattended and must fend for themselves with the danger of an overdose, underdose, or the use of an incorrect medicine.
Obviously, it would be very beneficial for a vision impaired person to be able to use a simple, safe and inexpensive assembly for a neeedle injector with little training, and which would enable independent injection by the user.